Cylinder for opposed-piston internal combustion engines



Aug 24 1943.

J. BARRAJA-FRAUENFELDER ErAL CYLINDER FOR OPPOSED- PISTON INTERNALCOMBUSTION ENGINES Filed Feb. 20, 1943 I INVENTORS Jos 9,06 B 0/7III/111,1

ay'a-fi-emen/e/der BY OscarGSchrom /& A RNEY Patented Aug. 24, 1943CYLINDER FOR OPPOSED-PISTON INTER- NAL COMBUSTION EN GINES' JosephBarraja-Frauenfelder, Upper Montclair,

and Oscar G. Schrom, Montclair, N. J., assignors to American LocomotiveCompany, New York, N. T2, a corporation of New York Application"February so, 1943, Se'rialNo. 476,590

This invention relates to a power cylinder for an internal combustionengine .of the opposedpistontype.

In engines of the aforesaid type it is customary to reinforce the lineradjacent the combustion chamber, as by means of an externally encirclingintegral collar forming a part of the liner. When thecylinder liner isjacketed for the circulation of water or other cooling medium, means areusually provided in the collar permitting pas sage of cooling mediumtherethrough, as for instance a series of boresextending through thecollar, the means forming part of the circulating system for the coolingmedium and serving to cool the reinforced portion of the liner.

The object of the present invention is to pro Vide a cylinder liner, foran engine of the aforesaidtype, of an improved construction for moresatisfactorily circulating the cooling medium, and particularly for moreefiiciently cooling a reinforced portion of the liner adjacent thecombustion chamber of the cylinder.

Referring to the drawing forming apart of this application, Figure 1 isa fragmentary sectional view of the cylinder assembly of an engineembodying the present invention, taken on the line I--I of Fig. 2, twopistons being shown fragmentally in section; Fig. 2 is a sectional viewof the cylinder assembly of Fig. 1, taken on the line l1-II thereof;Fig. 3 is a plan View of a portion of the, cylinder liner of Fig. 1';Fig. 4 is a view similarto Fig. 3, showing a modified construction; Fig.5 is an enlarged section on the line V-V of Fig. 4; and Fig. 6 is alongitudinal central sectional view of aportion of the cylinder liner ata stage in the process of its manufacture.

The invention, relates to internal combustion engines of theopposed-piston type generally.

The cylinder assembly of such an engine is shown in the accompanyingdrawing but only toan extent suificient for a clear understanding of thepresent invention. l

The cylinder assembly comprises a cylinder liner l and a jacket 2. Theliner is provided with axially-spaced integral collars 3 which thejacket snugly engages, the collars '3 and jacket having aligned orificesproviding ports 4.

The cylinder is provided with opposed pistons 5--5 shown in Fig. 1 intheir outermost positions.- The transverse center plane of the cylinder(cylinder liner) isindicated by, adot-dash line a. When the pistons arein their outermost positions, one at each side of and spaced from theplane a, they, together'wit h the portion of the liner in the spacetherebetween, define the complane in the plane a (see Fig; 6).

g 2 Claims. (o1.123+173 bustion chamber, all in the usual manner, theengine .1311115 far described being conventional. The plane a is alsothe transverse center plane of the cylinder combustion chamber;

In the manufacture of the cylinder liner of the present invention anintegral collar 1) is formed externally'on the liner with its transversecenter It has a central cylindrical peripheral portion 0 and at each endthereof a frusto-conical portion 02, the portions 0 and (1 beingconnected by concave fillet-like portions e. 'The'collar b may beformed. by suit- The present invention comprises a liner having acircumferential row of fins on its outer surface I adjacent the cylindercombustion .chamberflthe fins beingfspaced to provide passages for theflow of the cooling medium. The fins are preferably formed by cutting ormachining the collar 1), as will later, more fully appear.

Referring to Figs. 1, 2 and 3, the liner is pro vided with acircumferential row of fins ii, the

fins being separated one from another by spaces .1. Thefins-fi and thespaces 1 cross the plane a,

and extend therefrom at each side thereof. They are disposed adjacentthe cylinder combusion chamber andextend in a direction axially of theliner. M v The fins fi are formed from the collar b by cutting thecollar away to provide the spaces '5. The fins comprise facial portions0', d and e corresponding respectively to the portions :2, d and e ofthe collar b. l

The jacket 2 snugly engages the fins at the portions 0 and bridges thespaces 1 therebetween, the spaces thereby providing a circumferentialrow of passagesS. At each end of the row of fins the jacket 2 is spacedfrom the liner whereby Here the liner I 4 is provided with fins I5 andintervening spaces I6 which are disposed at an angle to its axis a: ofits cylinder. The method formerly described of forming the fins 6 andintervening spaces I shown in Figs. 1 to 3, where the revolving circularcutter was moved toward and away from the axis I'm as it was passed alonthe collar b from end to-end thereof, is not adapted for forming thefins I5 and intervening spaces I6. Here a simpler method is followed.

a The. cutting tool, as forinstance thev revolving lengths and heightsand they aresuitably 'proportioned as to width about the circumferenceof the liner to provide ample heat exchange' between the fins, linerportions therebetween, .;and:the'

Cooling water flowing through the passages .8. Consideration however isgiven in forming the fins to give them suflicient width to afford therequired reinforcement for the liner at the combustion chamber portionthereof where the fins are located.

A further feature of the -inventionis to provide the liner portionswhich are :with'in'the spaces .1 between the fins of graduallydecreasing thickness *from the outer ends of the spaces toward thecenter, with aminimum: thickness at-the plane a. This is accompanied bya corresponding. gradual approach of the bases of the fins toward theinterior face of the liner, this approach being from the ends of thefins toward the plane a, :and being of a maximum degree-at the planed,that is to say, they approach nearest to the liner interior face at theplane a. These characteristics of the liner portions within the spaces1, and of thefins, -lends toward better heat transfer adjacentthe thedesired circumferential intervals, the spaces and fins will be formed. 7Where the spaces and fins. as in Figs. 1, 2 and 3, extend axially of theliner, the cutter will obviously likewise be fed alongthe collaraxially-ofthe liner.

The circular cutter is well adapted for-provid- "ing the aforesaidgradual decreasing thickness-in the wall of the iiner within'the spacesand the gradual approach of the bases of the fins'tow ard the inner faceof the liner. All that is necessary to accomplish "this when employing arevolving circular cutter "is' to feed it gradually toward the lineraxis x as it is moving from' an end of the collar 1) 'toward't-he planea and-to feed it graduall away from the liner axis in when it mov- 'ingfrom theyplanen toward the opposite end of circular cutter, is moved ina straight path through the collar b, in a plane parallel to the axis a:and at anangle to the axis similar to the angle ofthe corresponding finI5 and space I6 to be formed. 1

This method of producing the fins and inter-1 vening spaces instead ofproducing the lines f-Jf, which may be curved or straight as aforesaid,the straight lines forming an angle at the plane a, produces thestraight line 9' extending proachthe :axisac from their outer ends*tothe center or plane a. This is clearly shown in Fig. 5, Which'is anenlarged section of Fig. 4 taken on the line V- V'thereof.: Thischaracteristic is the result of cuttin exteriorly into the wall of theliner in a path obliquely. of its axis. The fin's li and spaces I6, inadditiontobeing provided-bye simpler method, .have .the furtheradvantagexof being longerthan the .fins 5 and spaces 1 formed from thesame sizeof collar b. [Furthermorethe fins I5 and spaces it being 'atwanangle to the axis a: produce ..a=turbulence in the flow .of 'the coolingwater, thereby increasing the heat transferrate. 1.

The liner of Figs. 1 to 3 furtherincludes a boss I! which isformedibysuitably cutting away the collar '17. The boss is disposedbetween two of the fins 5 and has its .ce'nter in the planexc.

In cutting away thecollar b toforrn the boss and portions of the 'twoadjacent .fins" 6, three short fins I8 with adjacent spaces I 9 areformed.

The jacket 2 snugly engagesnthe boss I1.- A similar boss 29', .shortfins '21, and adjacent spaces, 22 are "provided in the construction-ofFigs, 4 and .5, .exceptth'at here thebo'ss, short fins,,:and adjacentspaces-are inclinedsimilarly to the long finsand longspaces of thisconstrue tion.

. The 'bosslis forithepurpose ofprovidingmeans for securing axfixture(not shown) to the cylin cler assembly. There aresever-al oithese fixetures usually employed, such as fuel injectors,"*a. glow plug, and astarting valve, and 'there will accordingly be a corresponding number ofbosses provided, spaced circumferentially'at the plane a. The liner atthe bosses and the adjacent por tions of the jacket will be suitablyorificed (not shown) according to "the -requirements of' the particularfixtures to be connected thereto.

Figs. "4 and 5 show a'modified. construction.

While there have been hereinbefore-described approved embodiments Coi-this invention, it will be understood that many and various changes andmodifications in form, arrangement of "parts and details of constructionthereofmaybe made without departing from the spiritor the invenf tionand'that all such changes *and ,-modifications as fallwithin the scopeof the appended claims" are contemplated as apart of this invention.-

Nevertheless the fins I5 and spaces IB have- The invention claimed anddesired to be secured by Letters Patent is:

c 1. An opposed-piston internal combustion engine power cylindercomprising a cylinder liner having external integralcircumferentiallyspaced heat transfer fins extending across thetransverse center plane of the cylinder combustion chamber parallel tothe axis of said liner, the liner in the spaces between said fins havingits outer face at each side of said plane inclining inwardly toward saidaxis, said liner in said spaces thereby decreasing in thickness in adirection toward said plane and being of a minimum thicknesssubstantially at said plane; and a jacket surrounding said liner, spacedtherefrom at each end of said finsproviding chambers and engaging saidfins providing a sleeve therefor closing said spaces, the closed spacesproviding passages connecting said chambers and said chambers beingprovided one with an 20 inlet and the other with an outlet for the flowof a cooling fluid medium through said chambers and passages.

2. An opposed-piston internal combustion engine power cylindercomprising a cylinder liner having external integralcircumferentiallyspaced heat transfer fins extending across thetransverse center plane of the cylinder combustion chamber at obliqueangles to the axis of said liner, the liner in the spaces between saidfins having its outer face straight in a longitudinaldirection and at anoblique angle to said axis in a plane parallel to said axis, said linerin said spaces thereby, at each side of said plane, decreasing inthickness in a direction toward said plane and being of a minimumthickness substantially at said plane; and a jacket surrounding saidliner, spaced therefrom at each

